The subject matter described herein relates generally to wind turbines and systems for operating a wind turbine, and more particularly, to slip ring systems for enabling the transfer of electrical energy and electrical signals between single components of the wind turbine or between components of the wind turbine and external devices provided in the operation environment of the wind turbine.
Generally, a wind turbine includes a rotor that comprises a rotatable hub assembly having multiple blades. The blades transform wind energy into a mechanical rotational torque that drives one or more generators via the turbine rotor. The generators are sometimes, but not limited to, rotationally coupled to the turbine rotor by a gearbox. The gearbox steps up the inherently low rotational speed of the turbine rotor for the generator to efficiently convert the rotational mechanical energy to electrical energy. This energy is fed into an electrical grid via at least one electrical connection. Gearless direct-drive wind turbines also exist. The turbine rotor, generator, gearbox and other components are typically mounted within a housing, or nacelle, that is positioned on top of a base that may be a truss or tubular tower.
At least some known wind turbines include a tower and a nacelle mounted on the tower. A turbine rotor is rotatably mounted to the nacelle and is coupled to a generator directly or with the help of a shaft. A plurality of blades extends from the turbine rotor. The blades can be oriented such that wind passing over the blades turns the turbine rotor, thereby driving the generator to generate electricity.
In some wind turbines the blades are mounted rotatably along their longitudinal axis to the hub in order to adjust their angle of attack with regards to the rotational speed and the wind speed. In order to enable such a rotation of the blades the so-called pitch system is provided to the hub which can be electrically controlled by the control system of the wind turbine. Additionally or alternatively further electrical devices can be placed within the hub or the blades.
For enabling an electrical connection between the control system of the wind turbine and electrical components in the hub or in the blades an electrical connection apparatus must be provided for establishing an electrical connection between the rotating components in the hub/rotor and non-rotating electrical components within the nacelle of the wind turbine. Said electrical connection apparatus usually has a delicate and expensive design in order to insure an enduring and uninterrupted electrical connection between the rotating and the non-rotating electrical components.